The organization of an analog store is centered around a very-low-leakage capacitor having a very high leakage resistance coupled with a rather low capacitance. In order that the voltage which is to be stored can be picked up from a circuit without disturbing the operation of the latter, while at the same time ensuring rapid charging of the capacitor and keeping leakage to a minimum, it is customary to connect the capacitor to the voltage source via an input amplifier with a low output impedance in order to effect rapid charging of the capacitor. It is also desirable to provide an output amplifier of high input impedance in order to minimize the loss of charging voltage and electronic circuit breakers serving, during a sampling phase, to apply an input signal to the capacitor by way of the input amplifier and then, as soon as the sampling phase has ended and during a holding phase, to insulate the capacitor from the input amplifier and stabilize the stored voltage through feedback from the output amplifier.
Conventional analog-voltage stores of this type generally use amplifier circuits which must have strictly constant gain levels. In order to maintain an output voltage equal to the input voltage, the parameters of the components must be adjusted so that the product of the amplification factors in the circuit remains equal to unity. This requires very delicate adjustments.